volvo penta 280 SP leg upper swap to a DP-D or E lower

[creativeinnovation]

Hi everyone, I own a 1981 28 ft Campion with a command bridge, 350 small block chevy with a 280 stern drive SP, and a 1.61 lower ratio. I just purchased a DP-D or E, gunmetal grey in color, (perhaps a 290?) lower leg, and according to the numbers on the large(forward) shaft, the gear ratio is 1.78(3861458 part #), and the housing has the diesel type exhaust outlet(it's below the cavitation plate, oval shaped, not the same as the gasser exhaust like my original 280 lower)
Now, I've been reading alot of forums and talked to a few volvo penta mechanics, and I'm getting discrepancies between what I am reading and what I've been told. I was told that the DP-D or E won't work with the upper, the only reason I was told as to why it may not work is due to the ratios from the upper to the lower are not quite compatible, and things may "break", but that doesn't make any sense really IMO, to yes it will work no problem(with some shimming required for the tapered roller bearing). By what I can physically see is, the lower DP setup I just bought, looks really close to the 280 lower SP setup, mounting surface, size(the DP cavitation plate is slightly longer) and looks are almost identical, I even test fitted it to the upper and it bolts right up to all the mounting holes, the ONLY obvious part that's different is the vertical shaft, the DP is shorter, and the SP is longer, I was told that all I need to do to fix that is to install the longer sleeve in place of the short sleeve.
My question is, should there be any issues with this type of swap? I just don't want things "breaking" falling apart, ect while out in the middle of no where, or did I just waste my $ on something that will only work as a paper weight...BTW, I am willing to change out parts, convert, whatever it will take to make it work...

 

[Scott Danforth]

welcome aboard

if I recall, the DP_A is the last unit that will work with your transom shield, H-frame, etc. regarding just the lower, I believe its the DP-C as the last one, then they revised the mid-housing and a few other things.

you should be looking for a 290 290a or DP-A lower as those do fit without issue

also note the 1.78 ratio lower is from a big block or diesel. the 1.95 ratio lower is from small V8's and the 2.30 ratio is from V6's

what you have wont work for what you want to do

sell it, get your money back and get what you need. If you locate a good 290, 290a or DP1 in the 1.78 ratio, I have a 1.95 we could do a swap on.